Our microbiome is significant not only in our digestive response to foods, but to herbs as well.
Take this study as example. Researchers have identified over 60 ginsenosides in American ginseng (recently up from 32), “all of which are absorbed only from the intestines”. They go on to state that “most ginsenosides are metabolized in the stomach (acid hydrolysis) and in the intestine (bacterial hydrolysis), or transformed to other ginsenosides”. In vitro studies have indicated that ginsenoside Rb1 “is metabolized by human intestinal bacteria. Collective evidence suggests that the metabolism and transformation of intact ginsenosides is an important process, playing an important role not only in bioavailability but also in the potential health benefits of ginseng.”
This is particularly important when discussing ginseng since it helps explain why previous studies have yielded contradictory or inconclusive results when studying the affects of ginseng on a study group. Not only does American ginseng itself vary significantly based on its genetic lineage and environmental rearing, but the study subjects themselves have variant microbiomes that produce different, sometimes opposite, results. Undoubtedly this process is it play in other herbs and medicines as well.